<spanid="index-0"></span><h1>compute com command<aclass="headerlink"href="#compute-com-command"title="Permalink to this headline">¶</a></h1>
<divclass="section"id="syntax">
<h2>Syntax<aclass="headerlink"href="#syntax"title="Permalink to this headline">¶</a></h2>
<divclass="highlight-python"><divclass="highlight"><pre>compute ID group-ID com
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<ulclass="simple">
<li>ID, group-ID are documented in <aclass="reference internal"href="compute.html"><em>compute</em></a> command</li>
<li>com = style name of this compute command</li>
</ul>
</div>
<divclass="section"id="examples">
<h2>Examples<aclass="headerlink"href="#examples"title="Permalink to this headline">¶</a></h2>
<divclass="highlight-python"><divclass="highlight"><pre>compute 1 all com
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<divclass="section"id="description">
<h2>Description<aclass="headerlink"href="#description"title="Permalink to this headline">¶</a></h2>
<p>Define a computation that calculates the center-of-mass of the group
of atoms, including all effects due to atoms passing thru periodic
boundaries.</p>
<p>A vector of three quantites is calculated by this compute, which
are the x,y,z coordinates of the center of mass.</p>
<divclass="admonition warning">
<pclass="first admonition-title">Warning</p>
<pclass="last">The coordinates of an atom contribute to the
center-of-mass in “unwrapped” form, by using the image flags
associated with each atom. See the <aclass="reference internal"href="dump.html"><em>dump custom</em></a> command
for a discussion of “unwrapped” coordinates. See the Atoms section of
the <aclass="reference internal"href="read_data.html"><em>read_data</em></a> command for a discussion of image flags
and how they are set for each atom. You can reset the image flags
(e.g. to 0) before invoking this compute by using the <aclass="reference internal"href="set.html"><em>set image</em></a> command.</p>
</div>
<p><strong>Output info:</strong></p>
<p>This compute calculates a global vector of length 3, which can be
accessed by indices 1-3 by any command that uses global vector values
from a compute as input. See <aclass="reference internal"href="Section_howto.html#howto-15"><span>this section</span></a> for an overview of LAMMPS output
options.</p>
<p>The vector values are “intensive”. The vector values will be in
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